FinFET gate structure and method for fabricating the same
First Claim
1. A semiconductor device, comprising:
- a semiconductor substrate;
a first semiconductor fin on the semiconductor substrate; and
a n-type gate structure over the first semiconductor fin, wherein the n-type gate structure is fluorine incorporated and comprises;
a first initial layer over the first semiconductor fin;
a first high-k dielectric layer over the first initial layer and enclosed by a first gate spacer;
a n-type work function metal layer overlying the first high-k dielectric layer, the n-type work function metal layer comprising a TiAl (titanium aluminum) alloy or TaAl (tantalum aluminum) alloy, wherein an atom ratio of Ti (titanium) to Al (aluminum) is in a range substantially from 1 to 3 when the n-type work function metal layer comprises the TiAl alloy;
a first blocking metal layer overlying the n-type work function metal layer; and
a first metal filler peripherally enclosed by the first blocking metal layer, such that the first metal filler is enclosed by a first stacked structure, wherein a side wall of the first stacked structure contains a fluorine concentration substantially from 5 atom percent (at %) to 20 at %, and a bottom of the first stacked structure contains a fluorine concentration substantially from 1 at % to 15 at %.
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Accused Products
Abstract
A semiconductor device includes a n-type gate structure over a first semiconductor fin, in which the n-type gate structure is fluorine incorporated and includes a n-type work function metal layer overlying the first high-k dielectric layer. The n-type work function metal layer includes a TiAl (titanium aluminum) alloy, in which an atom ratio of Ti (titanium) to Al (aluminum) is in a range substantially from 1 to 3. The semiconductor device further includes a p-type gate structure over a second semiconductor fin, in which the p-type gate structure is fluorine incorporated includes a p-type work function metal layer overlying the second high-k dielectric layer. The p-type work function metal layer includes titanium nitride (TiN), in which an atom ratio of Ti to N (nitrogen) is in a range substantially from 1:0.9 to 1:1.1.
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Citations
20 Claims
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1. A semiconductor device, comprising:
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a semiconductor substrate; a first semiconductor fin on the semiconductor substrate; and a n-type gate structure over the first semiconductor fin, wherein the n-type gate structure is fluorine incorporated and comprises; a first initial layer over the first semiconductor fin; a first high-k dielectric layer over the first initial layer and enclosed by a first gate spacer; a n-type work function metal layer overlying the first high-k dielectric layer, the n-type work function metal layer comprising a TiAl (titanium aluminum) alloy or TaAl (tantalum aluminum) alloy, wherein an atom ratio of Ti (titanium) to Al (aluminum) is in a range substantially from 1 to 3 when the n-type work function metal layer comprises the TiAl alloy; a first blocking metal layer overlying the n-type work function metal layer; and a first metal filler peripherally enclosed by the first blocking metal layer, such that the first metal filler is enclosed by a first stacked structure, wherein a side wall of the first stacked structure contains a fluorine concentration substantially from 5 atom percent (at %) to 20 at %, and a bottom of the first stacked structure contains a fluorine concentration substantially from 1 at % to 15 at %. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A semiconductor device, comprising:
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a semiconductor substrate; a first semiconductor fin and a second semiconductor fin on the semiconductor substrate, wherein the first semiconductor fin and the second semiconductor fin are separated by an isolation structure; a n-type gate structure comprising a first initial layer over the first semiconductor fin and enclosed by a first gate spacer, and a p-type gate structure comprising a second initial layer over the second semiconductor fin and enclosed by a second gate spacer, wherein each of the n-type gate structure and the p-type gate structure is fluorine incorporated and comprises; a high-k dielectric layer over the first initial layer and the second initial layer; a first TiN layer overlying the high-k dielectric layer; a TaN layer overlying the first TiN layer; a second TiN layer overlying the TaN layer; a TiAl layer overlying the second TiN layer; a third TiN layer overlying the TiAl layer; and a metal filler peripherally enclosed by the third TiN layer, such that the metal filler is enclosed by a stacked structure, wherein a side wall of the stacked structure contains a fluorine concentration substantially from 5 at % to 20 at %, and a bottom of the stacked structure contains a fluorine concentration substantially from 1 at % to 15 at %; wherein the TiAl layer enclosed by the first gate spacer is a n-type work function metal layer, wherein an atom ratio of Ti (titanium) to Al (aluminum) is in a range substantially from 1 to 3; and the second TiN layer enclosed by the second gate spacer is a p-type work function metal layer, wherein an atom ratio of Ti to N (nitrogen) is in a range substantially from 1;
0.9 to 1;
1.1. - View Dependent Claims (13, 14, 15)
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16. A method for forming a semiconductor device, the method comprising:
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forming a first semiconductor fin and a second semiconductor fin on a semiconductor substrate, wherein the first semiconductor fin and the second semiconductor fin are separated by an isolation structure; depositing a first initial layer enclosed by a first gate spacer over the first semiconductor fin, and a second initial layer enclosed by a second gate spacer over the second semiconductor fin; depositing a high-k dielectric layer over the first initial layer and the second initial layer; depositing a first TiN layer over the high-k dielectric layer; depositing a TaN layer over the first TiN layer; depositing a second TiN layer over the TaN layer; depositing a TiAl layer over the second TiN layer; depositing a third TiN layer over the TiAl layer; depositing a metal filler peripherally enclosed by the third TiN layer by using a fluorine-contained precursor; and diffusing fluorine to a stacked structure enclosing the metal filler, such that a side wall of the stacked structure contains a fluorine concentration substantially from 5 at % to 20 at %, and a bottom of the stacked structure contains a fluorine concentration substantially from 1 at % to 15 at %. - View Dependent Claims (17, 18, 19, 20)
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Specification